A multi-prong approach was taken in this dissertation to understand volcanic processes from both a long-term and more immediate hazard perspective. In the long-term, magma sources within the crust may produce measurable surficial response and long-wavelength gravity anomalies that provide information about the extent and depth of this magma. Long-term volcanic hazard forecasting is also improved by developing as complete a record as possible of past events. In the short-term, a long-standing question has been on the casting of precursory volcanic activity in terms of future volcanic hazards. Three studies are presented in this dissertation to address these issues. Inversion of high-resolution ground magnetic data in Amargosa Valley, NV indicates that anomaly B could be generated by a buried shield volcano. This new information changes the event count in this region which in turn affects the overall volcanic hazard estimation. Through the use of Finite Element Models (FEM) an in-depth characterization of the surficial response to magma underplating is provided for the Tohoku Volcanic Arc, Japan. These models indicate that surficial uplift was dominantly driven by mid-crustal intrusions and the magnitude and wavelength of this uplift was mainly controlled by the elastic layer thickness. In Dominica, seismic data were used as weights in spatial intensity maps to generate dynamic volcanic hazard maps influenced by changes in seismicity. These maps show an increasing trend in the north that may be indicative of an increase in earthquake and volcanic hazards.

In this thesis I combine data from 29 volcanic earthquake swarms that follow the pattern predicted by the Generic Volcanic Earthquake Swarm Model (GVESM; Benoit and McNutt, 1996) to investigate whether the relative timing of various parameters of pre-eruptive volcanic earthquake swarms could be used to forecast the time of an impending eruption. Based on the analysis of seismic unrest preceding many eruptions, the GVESM suggests that it is common to see an increase first in high-frequency earthquakes, then low-frequency earthquakes, then the onset of volcanic tremor. While this pattern is useful to volcano-seismologists, the relative timing and durations of these three different types of volcanic seismicity, is explored here for the first time. The parameters investigated are the onset times of (i) low-frequency (LF) events and of (ii) tremor, and the time at which (iii) the peak rate (PR) of volcano-tectonic (VT) events and (iv) the maximum magnitude (MM) earthquake occur in relation to normalized time defined by swarm onset and end (i.e., eruption). The normalized time starts at the swarm onset (0%) and ends with the eruption (100%) allowing a comparison and joint consideration of parameter occurrences across swarms of different actual duration. We identify the normalized onset time of for each parameter (LF, tremor, PR, MM) with respect to the duration of each swarm. Each swarm has onset time uncertainties of the swarm itself and of its parameters. A swarm with large onset uncertainty could bias the normalized onset time of each parameter and we use weighted means to decrease the influence of swarms with large uncertainties on overall results. The weighted means of LF onset, tremor onset, MM and PR occurrence are 79% ± 23%, 96% ± 10%, 78% ± 29% and 75% ± 34%, respectively. Errors are the standard deviation of each parameter. The uncertainties for LF, MM and PR are large because their normalized onset times have the characteristics of a uniform distribution and therefore seem to have no predictive value. In contrast, tremor onset has a narrow distribution towards the end of swarms. A possible tremor mechanism consistent with this observation could be boiling of groundwater as magma nears the surface. LF onset always seems to precede tremor onset. LF and tremor start early (at less than 80% of normalized time) at five volcanoes with high SiO2 content possibly related to lower density and higher gas content of the resulting magma.

Four geophysical methods, along with well logs and outcrop data, were used in determining the location of a fault situated on the campus of Oregon Institute of Technology, just north of Klamath Falls, Oregon. The fault displaces rocks of the Yonna Formation, of Pliocene age. Wells located northeast of the fault (on the upthrown side) produce cold water, and wells located southwest of the fault (on the downthrown side) produce hot water. The purpose of this investigation was to define the characteristics of the fault exposed behind a large water tank southeast of the OIT campus.

The geologic setting of the Portland Basin is ideal for gravity surveys because of the large density contrasts between geologic units. The Portland Basin consists of a north-northwest-trending syncline in the Columbia River basalt overlain by Pliocene to Recent alluvium. This study was undertaken to define structures in the Portland Basin which are obscured by the alluvium. An areal gravity survey of the Portland Basin covering approximately 450 square kilometers was conducted for this study.

p.p1 {margin: 0.0px 0.0px 0.0px 0.0px; font: 12.0px 'Times New Roman'} A methodology is presented for evaluating the potential surface fault displacement on reverse faults in a probabilistic manner. This methodology follows the procedures put forth for Probabilistic Fault Displacement Hazard Analysis (PFDHA). Empirical probability distributions that are central to performing a PFDHA are derived from field investigations of reverse faulting events. Statistical analyses are used to test previously assumed properties of scale invariance with respect to magnitude for normalized displacement. It is found that normalized displacement is statistically invariant with respect to magnitude and focal mechanism, allowing for the combination of a large number of events into a single dataset for regression purposes. An empirical relationship is developed using this single dataset to be used as a fault displacement prediction equation. A PFDHA is conducted on the Los Osos fault zone in central California and a hazard curve for fault displacement is produced. A full sensitivity analysis is done using this fault as a reference, to test for the sources of variability in the PFDHA methodology. The influence of the major primary variables is quantified to provide a future direction for PFDHA.

Book summary: In the newly revised Second Edition of the Handbook of Archaeological Sciences, a team of more than 100 researchers delivers a comprehensive and accessible overview of modern methods used in the archaeological sciences. The book covers all relevant approaches to obtaining and analyzing archaeological data, including dating methods, quaternary paleoenvironments, human bioarchaeology, biomolecular archaeology and archaeogenetics, resource exploitation, archaeological prospection, and assessing the decay and conservation of specimens [...]

Ground penetrating radar (GPR) is limited by the depth of penetration and signal-to-noise ratio (SNR), which both impact the ability to resolve subsurface features. GPR antennas are known to have limited depth penetration due to the noise and signal attenuated. The noise floor is the depth at which there is no discernable signal (Stec and Susek 2018). SNR is the comparison of desired signal to background noise, understanding that noise is any unwanted signal. Different objects in the environment can transmit frequencies that are recorded in data as background noise; this noise is considered to be external noise. Internal noise is noise which is generated by the internal components of the GPR system. Data processing such as filtering can reduce noise. Noise that occurs at the same frequency as the signal of interest, however, cannot be filtered out without also removing the signal of interest.

<p>In 2009, the Regional Municipality of Halton and McMaster University initiated a 2-year collaborative study (Georgetown Aquifer Characterization Study-GACS) of the groundwater resource potential of Quaternary sediments near Georgetown, Ontario. As part of that study, this thesis investigated the Quaternary infill stratigraphy of the Middle Sixteen Mile Creek (MSMC) and Cedarvale (CV) buried valley systems using newly acquired core and borehole geophysical data. Multi-parameter geophysical log suites (natural gamma, EM conductivity, resistivity, magnetic susceptibility, full-waveform sonic, caliper) were acquired in 16 new boreholes (16 m to 55 m depth), pre-existing monitoring wells and from archival data. Characteristic log responses (electrofacies) were identified and correlated with core to produce a detailed subsurface model of a 20-km² area to the southwest of Georgetown. Nine distinctive lithostratgraphic units were identified and their geometry mapped across the study area as structure contour and isochore thickness maps. The subsurface model shows that the CV valley truncates the Late Wisconsin MSMC stratigraphy along a channelized erosional unconformity and is a younger (post-glacial?) sediment-hosted valley system. Model results demonstrate the high level of stratigraphic heterogeneity and complexity that is inherent in bedrock valley systems and provides a geological framework for understanding groundwater resource availability.</p> <p>Principal component analysis (PCA) was applied to selected log suites to evaluate the potential for objective lithologic classification using log data. Gamma, resistivity and conductivity logs were most useful for lithologic typing, while p-wave velocity and resistivity logs were more diagnostic of compact diamict units. Cross plots of the first and second principal components of log parameters discriminated silts and clays/shales from sand/gravel and diamict lithofacies. The results show that PCA is a viable method for predicting subsurface lithology in un-cored boreholes and can assist in the identification of hydrostratigraphic units.</p> / Master of Science (MSc)

The Big Clifty (Jackson) Sandstone Member of the Golconda Formation is the most important of the Mississippian (Chesterian) heavy-oil reservoirs in the southeastern Illinois Basin. Heavy oil reservoirs, or asphalt rock deposits, have been studied extensively in south central and western Kentucky, and ~2 billion barrels of original oil in place (OOIP) have been proposed to occur in the Big Clifty Sandstone. Despite high OOIP estimates, heterogeneities in the reservoir negatively impact the production of heavy oil deposits. Heterogeneities related to depositional facies changes are poorly understood in the Big Clifty Sandstone of Kentucky, where it has been mostly described as a 60-120 feet thick sandstone unit. In some locations, the Big Clifty occurs as two distinct sand bodies with intercalated mud-rich units and, most typically, with the greatest clay- and silt-rich units present between sandstone bodies. Questions exist as to how such muddy facies occur in the reservoir. This study couples sedimentary facies analysis with sequence stratigraphy to assess how lithological factors affect the occurrence of petroleum in Big Clifty reservoirs. Multiple datasets were integrated to develop a depositional model for lithologic facies observed in this study. Datasets include core, exposure descriptions, petrographic analysis, bitumen concentrations, electrical resistivity tomography (ERT), and borehole geophysical analysis. This study occurred in Logan, Warren, and Butler counties, with emphasis on an active asphalt-rock mine in Logan County. Surface geophysical methods aided in demarcating Chesterian limestones, sandstone bodies and, in particular, highly resistive heavy-oil laden Big Clifty channel bodies. In Warren County, located E-NE of the Stampede Mine, the Big Clifty coalesces into a single amalgamated sandstone channel or a series of superimposed stacked channels as observed in outcrop along Indian Creek at McChesney Field Station and at Jackson’s Orchard. In these locations, the tidal influence is subtle with large-scale trough cross bedding dominating, and the contact on the Beech Creek Limestone is sharp. Facies changes related to the environment of deposition greatly impact the quality of heavy-oil reservoirs and must be taken into consideration during exploration and siting of asphalt rock mines.

Increased groundwater withdrawals associated with agricultural irrigation in the Jackson Purchase have prompted questions related to groundwater availability and sustainability. Key factors in addressing these questions are understanding the extent and variation in thickness of the local hydrostratigraphic system, which is the upper part of the Mississippi Embayment aquifer system. Correlations of 70 gamma-ray well logs, and 49 resistivity logs were made across parts of the Jackson Purchase in Fulton and Hickman Counties in order to delineate the upper Claiborne aquifer and middle Claiborne confining unit. Commercial software (i.e. Petra 3.8.3) was used to generate cross sections, structure and isopach maps of the upper Claiborne aquifer, middle Claiborne confining unit, and middle Claiborne aquifer. The structure and isopach maps show the upper Claiborne aquifer and middle Claiborne confining unit thickening and dipping southwest into the embayment. In an effort to test different methods for mapping these hydrostatic units in the shallow sub-surface, surface electrical resistivity and a seismic walkaway sounding were acquired and compared with downhole geophysical logs at two well-constrained sites to test their limits for resolving these hydrostratigraphic units. Both electric resistivity and seismic geophysical methods were best able to image the Claiborne aquifer system when used together.